Doxorubicin is known to be an affective anti-neoplastic agent. Some of its derivatives also are known to have such activity. However, undesired side effects like cardiotoxicity and bone marrow toxicity limit its use. Several investigators have shown previously that liposome encapsulation of doxorubicin results in enhanced antitumor activity against liver tumors and decreased cardiotoxicity. However, because doxorubicin is highly hydrophilic, the encapsulation and stability of liposomal doxorubicin are poor, and as a result all known attempts to obtain a satisfactory liposomal doxorubicin formulation have failed.
A compound which has the antitumor activity of doxorubicin but is more amenable to liposome encapsulation would have significant therapeutic advantages. A long standing need exists for such a compound.